Parsing test additions

A big set of changes to add verification for computed style. Now the entire suite tests for both computed and inline styles.  Noteworthy changes:
- All units are converted to their correct px value for the expected results
- To avoid fractional decimal precision issues, floats in the actual and expected results are rounded to 3 decimal places. 
- A couple of the calc test cases allow for 2 possible expected results as it turned out was ok according the the spec but implemented differently in Blink & Webkit. This is all described inline.
- At this point, there are two open bugs that are some failures:
Webkit #129838 & Blink #367889 - inset complex calc() args vanish in serialized computed style
Webkit #124502 (webkit only) Shapes do not resolve dimensions specified in viewport units